Not only are Baroque designs for the complete altar wall of a chapel quite rare, but this sheet is all the more exceptional in view of the level of detail it exhibits. As a painter, Daniele Crespi did not produce many works like this one. However, seeing as he has been recognized for his great clarity of form and content, it is unsurprising that the subject matter of the altarpiece (the "Pietà") and its flanking ovals (Saint Anthony Abbot and Saint Catherine of Alexandria) can be clearly identified from this preliminary design. Integrating the figurative paintings within the built structure allows Crespi to work out the ways in which his painted compositions will fit into the larger structure and to think about the overall cohesiveness of the ensemble.